Glazed curtain wall constructions are formed of modular glazed window units and panel units which are normally pre-assembled and installed to structural members at the installation site.
With certain curtain wall constructions, the window and panel units must be installed from the exterior of the building and this requires extensive scaffolding, particularly, if the building is of substantial height.
In the typical curtain wall construction, both jambs, the header, and the sill of the window and panel units are normally mounted to structural members or adjacent units by screws or other fasteners, the installation of fasteners is a time consuming operation that is a substantial factor in the overall cost of the construction.